791 research outputs found
Temporal inabilities and decision-making capacity in depression
We report on an interview-based study of decision-making capacity in two classes of patients suffering from depression. Developing a method of second-person hermeneutic phenomenology, we articulate the distinctive combination of temporal agility and temporal inability characteristic of the experience of severely depressed patients. We argue that a cluster of decision-specific temporal abilities is a critical element of decision-making capacity, and we show that loss of these abilities is a risk factor distinguishing severely depressed patients from mildly/moderately depressed patients. We explore the legal and clinical consequences of this result
Intra-week spatial-temporal patterns of crime
Since its original publication, routine activity theory has proven most instructive for understanding temporal patterns in crime. The most prominent of the temporal crime patterns investigated is seasonality: crime (most often assault) increases during the summer months and decreases once routine activities are less often outside. Despite the rather widespread literature on the seasonality of crime, there is very little research investigating temporal patterns of crime at shorter time intervals such as within the week or even within the day. This paper contributes to this literature through a spatial-temporal analysis of crime patterns for different days of the week. It is found that temporal patterns are present for different days of the week (more crime on weekends, as would be expected) and there is a spatial component to that temporal change. Specifically, aside from robbery and sexual assault at the micro-spatial unit of analysis (street segments) the spatial patterns of crime changed. With regard to the spatial pattern changes, we found that assaults and theft from vehicle had their spatial patterns change in predictable ways on Saturdays: assaults increased in the bar district and theft from vehicles increased in the downtown and recreational car park areas
Gauge invariance, causality and gluonic poles
We explore the electromagnetic gauge invariance of the hadron tensor of the
Drell-Yan process with one transversely polarized hadron. The special role is
played by the contour gauge for gluon fields. The prescription for the gluonic
pole in the twist 3 correlator is related to causality property and compared
with the prescriptions for exclusive hard processes. As a result of we get the
extra contributions, which naively do not have an imaginary phase. The single
spin asymmetry for the Drell-Yan process is enhanced by the factor of two.Comment: 9 pages, 2 figures; References and acknowledgements added
Transverse Polarisation of Quarks in Hadrons
We review the present state of knowledge regarding the transverse
polarisation (or transversity) distributions of quarks. After some generalities
on transverse polarisation, we formally define the transversity distributions
within the framework of a classification of all leading-twist distribution
functions. We describe the QCD evolution of transversity at leading and
next-to-leading order. A comprehensive treatment of non-perturbative
calculations of transversity distributions (within the framework of quark
models, lattice QCD and QCD sum rules) is presented. The phenomenology of
transversity (in particular, in Drell-Yan processes and semi-inclusive
leptoproduction) is discussed in some detail. Finally, the prospects for future
measurements are outlined.Comment: small changes, references added, as finally published in Physics
Report
Genome scan of Diabrotica virgifera virgifera for genetic variation associated with crop rotation tolerance
Crop rotation has been a valuable technique for control of Diabrotica virgifera virgifera for almost a century. However, during the last two decades, crop rotation has ceased to be effective in an expanding area of the US corn belt. This failure appears to be due to a change in the insect's oviposition behaviour, which, in all probability, has an underlying genetic basis. A preliminary genome scan using 253 amplified fragment-length polymorphism (AFLP) markers sought to identify genetic variation associated with the circumvention of crop rotation. Samples of D. v. virgifera from east-central Illinois, where crop rotation is ineffective, were compared with samples from Iowa at locations that the behavioural variant has yet to reach. A single AFLP marker showed signs of having been influenced by selection for the circumvention of crop rotation. However, this marker was not diagnostic. The lack of markers strongly associated with the trait may be due to an insufficient density of marker coverage throughout the genome. A weak but significant general heterogeneity was observed between the Illinois and Iowa samples at microsatellite loci and AFLP markers. This has not been detected in previous population genetic studies of D. v. virgifera and may indicate a reduction in gene flow between variant and wild-type beetles
Parton distribution functions and quark orbital motion
Covariant version of the quark-parton model is studied. Dependence of the
structure functions and parton distributions on the 3D quark intrinsic motion
is discussed. The important role of the quark orbital momentum, which is a
particular case of intrinsic motion, appears as a direct consequence of the
covariant description. Effect of orbital motion is substantial especially for
polarized structure functions. At the same time, the procedure for obtaining
the quark momentum distributions of polarized quarks from the combination of
polarized and unpolarized structure functions is suggested.Comment: 17 pages, 2 figures, 1 table. Paper is accepted for publication in
Eur.Phys.J.
Nucleon spin-flavor structure in SU(3) breaking chiral quark model
The SU(3) symmetric chiral quark model, which describes interactions between
quarks, gluons and the Goldstone bosons, explains reasonably well many aspects
of the flavor and spin structure of the proton, except for the values of
and . Introducing the SU(3)-breaking effect
suggested by the mass difference between the strange and nonstrange quarks, we
find that this discrepancy can be removed and better overall agreement
obtained.Comment: 18 pages, Latex, 4 tables. Phys. Rev. D (in press, submitted/revised
in June/Nov 1996
Orbital Angular Momentum Parton Distributions in Light-Front Dynamics
We study the quark angular momentum distribution in the nucleon within a
light-front covariant quark model. Special emphasis is put into the orbital
angular momentum: a quantity which is very sensitive to the relativistic
treatment of the spin in a light-front dynamical approach. Discrepancies with
the predictions of the low-energy traditional quark models where relativistic
spin effects are neglected, are visible also after perturbative evolution to
higher momentum scales. Orbital angular momentum distributions and their
contribution to the spin sum rule are calculated for different phenomenological
mass operators and compared with the results of the MIT bag model.Comment: 14 pages; latex; 3 ps figure
The Luminosity, Colour and Morphology dependence of galaxy filaments in the Sloan Digital Sky Survey Data Release Four
We have tested for luminosity, colour and morphology dependence of the degree
of filamentarity in seven nearly two dimensional strips from the Sloan Digital
Sky Survey Data Release Four (SDSS DR4). The analysis is carried out at various
levels of coarse graining allowing us to address different length-scales. We
find that the brighter galaxies have a less filamentary distribution than the
fainter ones at all levels of coarse graining. The distribution of red galaxies
and ellipticals shows a higher degree of filamentarity compared to blue
galaxies and spirals respectively at low levels of coarse graining. The
behaviour is reversed at higher levels of coarse graining. We propose a picture
where the ellipticals are densely distributed in the vicinity of the nodes
where the filaments intersect while the spirals are sparsely distributed along
the entire extent of the filaments. Our findings indicate that the regions with
an excess of ellipticals are larger than galaxy clusters, protruding into the
filaments. We have also compared the predictions of a semi-analytic model of
galaxy formation (the Millennium Run galaxy catalogue) against our results for
the SDSS. We find the two to be in agreement for the galaxies and for
the red galaxies, while the model fails to correctly predict the filamentarity
of the brighter galaxies and the blue galaxies.Comment: 14 Pages, 2 tables, 11 figures, Accepted for publication in MNRAS,
new section added for a comparison with semi analytical models of galaxy
formation, substantial revisio
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